Coal-mining machine



(No ModeL) s SheetsSheet 1.

G. D. WHITGOMB.

. GOAL-MINING MACHINE. No. 280,544. Patented'July 3, 1883.

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G. D. WHITGOMB.

GOAL MINING MA HINB.

Pgtented July 3, 1883.

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(No Model.) 3 Sheets-Sheet 3.

G. D. WHITGOMB.

GOAL MINING MACHINE.

No. 280,544. Patented July 3, 1883.

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' UNITED STATES GEORGE '1). WHITOOMB,

PATENT OFFICE.

OF CHICAGO, ILLINOIS.

COAL-MINING MACHINE.

SPECIFICATION forming part of Letters Patent No. 280,544, dated July 3, 1888.

Application filed NovemberlO, 1882. (No model.) I

To all whom it may concern.-

Be it known that I, GEORGE D. WHITCOMB, a citizen of the United States, residing at Chicage, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Coal-Mining Machines, which are fully set forth in the following specification, reference being had to the accompanying drawings, in which Figure 1 represents a longitudinal vertical section of a coal-mining machine embodying my improvements; Fig. 2, a detail of the upper portion of Fig. 1, on an enlarged scale; Fig. 3, a detail plan of the valve-chest on a scale enlarged from that of Fig. 2; Fig. 4, adetail section taken on the line 00 m, Fig. 3, 011 same scale; Fig. 5, a similar section taken on the line 3/ 9 Fig. 3, on same scale; Fig. 6, a detail elevation of the front cylinder-head 011 same scale; Fig. 7, a detail section taken on the line 2 2, Fig. 6, on same scale; Fig. 8, an elevation of the packing-ring detached, shown in Fig. 7.

My present invention relates to coal-mining machines similar to that shown in Letters Patent No. 232,792, issued to me September 28, 1880, and in an application for patent hereto fore filed by me, June 12, 1882, and allowed October 5; and it consists in certain improvements up on the machines shown and described in said patent and application.

I will proceed to describe in detail the con struction and application of my present im provements, referring to such portions of the machines heretofore shown and described by me as may be necessary for this purpose.

My present improvements are for the purpose of perfecting the machines in such parts as have been found desirable by actual use. The blow struck by the engine is very heavy, and a great strain is brought upon the pick and other parts of the machine. The effective work of the machine is also dependent upon tightness of the joints about the piston. If there is leakage, especially at the front end of the piston, the operation is greatly impaired. I have also found difficulty in regulating the supply of compressed air to the valve-engine. The quantity of air required to drive this e11- gine is comparatively small. and the regula tion is therefore comparatively fine. Expo rience has proved that in operating an air-compressor at or near a coal mine a large amount of dust is taken in with the air and becomes mixed with the condensed water in the pipes. It is also found that the oil used for lubricating machinery run by compressed air is liable to congeal. Consequently in regulating entirely by the inlet-port the port is necessarily made so small as to cause trouble by its becoming clogged by the dust and congealed oil. To avoid this difficulty I at first attempted to regulate at the exhaustport, but experienced difficulty from back-pressure. I have therefore adopted a twofold regulation at both inlet and outlet. I also have found it an improvement-to place the regulating stop-valve of the inlet in the port between the gate and eccentrio of the rotary engine,rather than (as shown in my Patent No. 232,7 92) in the port between the gate and the main valve-chamber, since a stop valve in the latter situation impairs the pressure requisite to hold the gate to the co centric. My present improvements are intended to obviate these several difficulties, and thereby improve the efficiency of the machine for practical use.

The main features of the machine are like those of the similar machine shown in my pat ent and application mentioned above, and do not require description here;

In the drawings, A represents the cylindrical chamber, in which the cylinder or piston B of the rotary engine that operates the valve is arranged to revolve. ordinary construction, and the engine is provided with the usual gates or valve, C, arranged upright in the frame-work, and resting on its lower edge upon the eccentric hub or piston.

The supply of compressed air is let into a chamber, D, as in my prior machines, from which leads an air-passage, E, extending up and opening in over the gate, which at its lower end is cut away on the side next to the These parts are of passage part way across, as seen in Fig. 2 of 5 the drawings. The air therefore is admitted over the gate, and holds the latter down upon the rotary piston, which, as usual, is mounted eccentrically in its chamber.

The inlet-port F of the engine is arranged, as usual, on one side of the gate, between which and the upright is the partition G, in the up per portion of which is an aperture, 9, opening from the gate-space into the inlet, so that as the gate drops in following the surface of the piston, and passes below the aperture 9, air will be admitted to the inlet and pass directly to the piston, as usual.

A cap, a, is arranged over the machine, covering all the openings mentioned, and in this cap is arranged a screw stopalive, 0, which passes down through the cap and enters the upper end of the inlet-port, as shown in Fig. 5 of the drawings. The cap is provided with a suitable stuiiing-box, through which this stop-valve passes down into the inlet-port far enough to entirely close the opening g in the partition, if desired, and consequently affords a means for regulating with nicety the size of this opening, thereby governing the admission of air to the inlet-port. At the same time the pressure of air on the gate, whereby it is held down to the eccentric B, is not diminished. I am enabled to secure this result easily by arranging the inlet-port as described above and extending it up through the chest under the cap. The outlet-port or exhaust-port H also extends upward and outward from the chamber on the other side of the gate, and near its end finds an outlet through a side passage, 71, the upper end of the port being closed with a screw-plug, h. A screw stop- *alve, H, is inserted from the other side of the chest into the exhaust-port, so as to close the side opening, 71, at pleasure, and hence also to regulate the opening through which the air escapes into this side passage, thereby regulating the exhaust in a similar way as the supply is regulated. This stopvalve passes through a suitable stuiiingbox inserted in the side of the chest.

It is obvious from the construction described above that both the supply and exhaust of the valve-engine may be nicely regulated, so as to work in unison, thereby keeping the air-pressure upon the top of the gate substantially uniform, and also enabling me to regulate the supply of air to the engine with great nicety. The main cylinder I and piston I are substantially the same as in my application mentioned above, and are constructed to obtain the cushioning effect therein set forth. At the front end of the cylinder there is also a packing, '1 for the piston-rod, as in the case mentioned. I have found, however, that under the great shock occasioned by the stroke there is great danger of leakage of air, and when this occurs the cushioning effect is lost. I have therefore provided an additional security against this leakage by also putting a packing in the cylinder-head J, and construct ed in a peculiar manner. The inner end of this cylinder-head is recessed, the recess being stepped, as at j j j". (Shown in Fig. 7 of the drawings.) I provide a packing, K, which is adapted to lit the smaller portion of the recess, and is made in the form shown in Fig. '7, being composed of an annular portion, is, and an outwardly-proiecting flange, k, which is adapted to rest on the seatj. The outside of the annular portion is beveled, and over this packing is fitted a suitable packingring, L, which is angular in cross-section, one portion, I, resting upon the flange of the pack ing, and the other outwardly-projecting portion, Z, resting on the step j. This ring holds the packing in place, and when these parts are in position, as shown in Fig. 7 of the drawings, there will be asmall tapering space be tween the packing and the ring, opening inward toward the cylinder. The headis fitted upon a flange, i, on the outside of the cylinder, which tits against the step j as in the machine shown in my prior application.

I have found this improvement of very great utility. If, from any cause, there should be a slight leakage from the cylinder around the piston, or the packing thereof in the end of the cylinder, it will find its way to the packing in the cylinder-head, where it will only tend to tighten the latter on the piston by entering the space between the packing and the packing-ring and pressing the former more closely upon the piston. The amount of air escaping in any event would be slight; but this slight amount is sufficient to impair the operation described in my prior application.

The improvement in the packing described above will prevent even this slight leakage. 4

Some modifications may be made in the con struction and arrangement of the devices mentioned above without departing from the leading features of my improvements.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The gate (1, in combination with the inlet-port F, extending upward through the chest, the partition G, provided with the aperture g, and the stop-valve 1), arranged in the inlet port to regulate the supply of air, sub stantially as described.

2. The gate 0 of the valve-engine, in combination with the inlet-port F, the partition G, provided with aperture g, regulating-valve I), exhaust-port H, and regulating-valve l-I, substantially as and for the purposes set forth.

The cylinder I, in combination with the piston I, the packing '1', the cylinder-head J, and the beveled packing K, substantially as and for the purposes set forth.

I. The cylinder I, provided with packing i, in combination with the cylinder-head .T, beveled packing K, and packing-ring L, substan tially as and for the purposes set forth.

GEO. l). \VHIITCOMB.

\Vitnesses:

JNo. (l. MAcGREooi-z, TnoMAs H. lu-xsn. 

